The Government is failing to tackle online Islamic extremism, according to a new report.

An in-depth study of people who support jihadist groups found that platforms like Facebook, Twitter and YouTube were still fuelling radicalisation.

The report, by the counter-extremist thinktank Quilliam criticised the government strategy of censorship and filtering, saying it was an ineffective, costly and counter-productive means of countering extremism.

"Currently there's a large focus for governments to use censorship, blocking and terrorist-related content," said Dr Erin Marie Saltman, research project officer at Quilliam.

"Censoring, filtering and blocking doesn't necessarily work. You can take down a website and it can go viral 10 seconds later."

"If a young individual who is a vulnerable individual goes online and wants to find out more…it is highly likely that (he is) going to reach propaganda and narratives," Dr Saltman added.

"We need a much more effective system of counter-speech so that when young individuals have questions…they have a resource online that gives a different message that explains why going and fighting in a foreign country is not the right thing to do."

One former extremist who was radicalised as a teenager said more work needed to be done to address the root causes of radicalisation.

"A lot of Muslims will feel a sense of injustice. It's usually something to do with the foreign policies in the West. They will start with these grievances which a lot of Muslims will agree with," said Hakim.

Hakim, who was influenced by material obtained by his brothers at university where radical Islamic groups were active, said he fully embraced extreme material.

"I started reading this stuff and then started proselytising at home," Hakim said.

"I was coming out with stuff that my siblings disagreed with - I remember specifically having a disagreement with my older brother about whether or not we should be chopping people's hands or feet off when they stole something."

The Government recently revised its strategy of dealing with online radical content, and said it acknowledged more needed to be done.

But the report says that the policy of censoring online material fails to recognise that many people are already radicalised through human contact, often at universities or in prison, and turn to the internet specifically looking for radical content.

"More could be done. Moderate scholars need to be empowered," said Hakeem.

"I don't think that extremist clerics or groups should be allowed to proselytise at educational institutions, that's not what they are for."